Rotary seal apparatus for permitting the transfer of fluid from a stationary housing into a rotating tube or shaft without excessive oil leakage.
U.S. Pat. Nos. 3,565,187 and 3,613,804 disclose hydraulically actuated chuck apparatus that includes a chuck having a rotary housing extended into a stationary housing with hydraulic fluid under pressure transferred from the stationary housing into the rotary housing and some fluid permitted to leak through a clearance gap between the housings and return to the sump. U.S. Pat. No. 3,103,144 discloses a hydraulically operated collet clamp having a rotatably driven sleeve with an axial passage therein for conducting hydraulic fluid to a collet mounted thereon. A rotary seal is provided between the drive sleeve and a stationary housing from which hydraulic fluid is transferred to the passage in the sleeve. Leakage fluid passing between the rotary sealing surfaces passes through bearings that rotatably mount the sleeve on the housing and is returned to the sump.
U.S. Pat. No. 4,294,454 discloses a stationary housing having spaced seal rings that each carries a seal ring and a shaft that mounts adjacent seal rings which are resiliently urged apart to sealingly contact the respective last mentioned seal ring and provide a fluid flow path between a housing passage and a shaft passage. U.S. Pat. No. 3,122,373 discloses a housing and a shaft wherein two seals under fluid pressure are urged axially apart to form fluid seals with axially spaced seal members.
In order to provide improved rotary seal mechanism between a stationary housing and a rotary drivable member such as a tubular spindle or shaft to enable high pressure hydraulic fluid to be transmitted from the housing to a passage in the drivable member with limited fluid leakage, this invention has been made.